1. Field of the Invention
This invention generally relates to robot assemblies that are used to remove molded items from molding machines, and more specifically, to robot assemblies that are used to remove items, referred to as lens curves, from high speed automated molding machines. Even more specifically, the invention relates to a split collar design for use on such robot assemblies.
2. Background Art
In the last several years, various molding machines have been developed to mold lens curves on a high speed, automated basis. These lens curves are then used to mold contact lenses. Such systems are disclosed, for example, in U.S. Pat. No. 5,702,735 and U.S. patent application Ser. No. 09/305,886 filed May 5, 1999 for “Mold and Molding Machine for Making Ophthalmic Devices”. In these systems, robot assemblies are commonly used to remove the lens curves from the molding machines.
In the operation of these molding machines, more specifically, two mold sections, or halves, are closed, a plastic is injected into the machine to form two types of lens curves, referred to as front and back curves, and the mold is then opened. An arm of the robot assembly is inserted between the mold sections to grip or engage the front and back curves, and then the robot arm carries those curves away from the molding machine.
Molding machines of this type have been successfully developed that operate on a high speed, mass production basis. In these high speed operations, the robot assemblies also operate at comparatively high speeds, and because of this, it becomes necessary occasionally to replace worn or damaged parts of the robot assemblies.
In particular, the robot arm, or components of the arm, occasionally needs to be replaced. In part, this is due to the fact that, in operation, the arm rapidly moves to and fro, into and then out of the molding machine, engaging, carrying and then releasing the front and back curves.
Replacing the arm can be difficult, however, due to machine guarding and limited access to the robot assembly for personnel and tools. Moreover, it is highly desirable to replace the arm quickly since the operation of the robot assembly, and the entire molding system, is interrupted while the arm is being replaced.